Inclusion of Polymers within the Crystal Structure of
Tris(<i>o</i>-phenylenedioxy)cyclotriphosphazene
Harry R. Allcock
A. Paul Primrose
Nicolas J. Sunderland
Arnold L. Rheingold
Ilia A. Guzei
Masood Parvez
10.1021/cm980611e.s001
https://acs.figshare.com/articles/journal_contribution/Inclusion_of_Polymers_within_the_Crystal_Structure_of_Tris_i_o_i_-phenylenedioxy_cyclotriphosphazene/3595365
Tris(<i>o</i>-phenylenedioxy)cyclotriphosphazene was found to form hexagonal host−guest
inclusion adducts (clathrates) with the polymers:  <i>cis</i>-1,4-polybutadiene, <i>trans</i>-1,4-polyisoprene, polyethylene, poly(ethylene oxide), and polytetrahydrofuran. Single-crystal X-ray
diffraction studies of both the polyethylene and poly(ethylene oxide) inclusion adducts
revealed the presence of individual polymer chains extended along tunnel-like voids within
the host lattice. Both polyethylene and poly(ethylene oxide) were incommensurate within
the tunnel-like voids preventing the exact elucidation of the polymer conformation. Average
repeat unit lengths calculated for these polymers suggest that both are in an extended
conformation. Both the polyethylene and poly(ethylene oxide) adducts crystallized from
benzene in the space group <i>P</i>6<sub>3</sub>/<i>m</i>. Inclusion adducts of the five different polymers were
examined by differential scanning calorimetry (DSC) and powder X-ray diffraction. In each
case, the melting point of the inclusion adduct was higher than either the melting point of
the pure polymer or the pure host. The melting points of oligomeric polyethylene and poly(ethylene oxide) inclusion adducts increased as the molecular weight of the included oligomers
increased. Removal of <i>cis</i>-1,4-polybutadiene and poly(ethylene oxide) from the host lattice
was achieved through chemical decomposition of tris(<i>o</i>-phenylenedioxy)cyclotriphosphazene.
Linear polybutadiene was separated from a mixture with highly branched polybutadiene
through selective adduct formation.
1999-04-28 00:00:00
polybutadiene
phenylenedioxy
DSC
poly
inclusion adducts
oxide
polymer
host lattice
polyethylene